I really need to save this as like a word file, I keep having to go back through old posts to avoid typing it all again.
First: what I am about to say is a generalization and there are exceptions. but generally...
Generally, mountains affect climate. Clouds and rain are carried by winds that tend to blow in the same patterns. When clouds hit mountains, they dump their rain, causing lush forests. But on the other half of the ridge, there is no rain and a desert is created. a wonderful example of this is Northern California vs Nevada. As you go over those mountains you go from forests, strawberry farms, and wineries to slat flats and cacti.
Certain general worldwide patters (caused by the earths rotation) are shown on this map:
Attachment 42596
Exceptions are common, for example this is how winds generally are:
Attachment 42597
These rainfall areas will affect multitudes of other things as well. Winds coming off deserts will be warm; one of the reasons for the warmth of europe is the wind from the sahara. If you compare southern France with Maine and you will see a vast difference in climates despite similar latitudes.
Here, for reference, is a map of Europe's Topography:
Attachment 42965
And here, a map of the Rainfall, with a strong correlation between changes in altitude and a massive dumping of rain.
Attachment 42967
Once again, there are exceptions, but just think about this before placing major mountain ranges.
Finally; USE AN EQUIRECTANGULAR PROJECTION. if you use one and decide later you want to re-project it there is a simple and easy to use piece of software that will do it for you. if you use something else, you will have to do it by hand. details on the equirectangular projection can be found at this link:http://en.wikipedia.org/wiki/Equirectangular_projection
But basically, the x-axis is Longitude and the y-axis is Latitude.